import sys
from PySide2 import QtWidgets, QtGui, QtCore

class MyDialog(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super(MyDialog, self).__init__(parent)
        layout = QtWidgets.QVBoxLayout()
        buttons = QtWidgets.QDialogButtonBox(
            QtWidgets.QDialogButtonBox.Ok |QtWidgets.QDialogButtonBox.Cancel,
            QtCore.Qt.Horizontal, self)
        buttons.accepted.connect(self.accept)
        buttons.rejected.connect(self.reject)
        layout.addWidget(buttons)
        self.setLayout(layout)

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    win = MyDialog()
    result = win.exec_()
    print(result)
    sys.exit(app.exec_())